Series 21


Generic Type

Phenalkamine Epoxy

Common Usage

High solids, immersion-grade coating offering exceptional build per coat for long-term corrosion resistance. For use on the interior and exterior of steel or concrete tanks, reservoirs, pipes, valves, pumps, and equipment, as well as other steel and concrete substrates. Specially formulated to meet the latest requirements for use in potable water applications.

Special Qualifications

Certified by NSF International in accordance with NSF/ANSI/CAN Std. 61 and the extraction requirements of NSF/ANSI/CAN 600. Series 21 is qualified for interior use on tanks and reservoirs, pipes, fittings, valves, and pumps. Reference Tnemec’s certified product listing at for additional details.

Series 21 conforms to AWWA C 210.

Conforms to AWWA D102 Inside Systems No. 1, 2, 5, and 6.

A two-coat and three-coat system of Series 21 meets the requirements of AWWA C550 Protective Interior Coatings for Valves and Hydrants. Contact your Tnemec representative for more information.

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Number of Components

Two: Part A (epoxy) and Part B (amine)


Series 21, 22, FC22, 72, 73, 406, 1028, 1029, 1094, 1095, 1096. Note: A 14-day maximum recoat time applies when topcoating with Series 22, FC22. A 30-day maximum recoat time applies when topcoating with itself and Series 72, 73, 406, 1028, 1029. A nine-month maximum recoat time applies when topcoating with Series 1094, 1096. A 12-month maximum recoat time applies when topcoating with Series 1095.

Curing Time

Temperature To Handle To Topcoat Potable Water Immersion
90°F (32°C) 2 hours 4 hours 7 days
75°F (24°C) 3 hours 5 hours 7 days
65°F (18°C) 5 hours 9 hours 8 days
55°F (13°C) 12 hours 18 hours 10 days
45°F (7°C) 20 hours 24 hours 12 days
40°F (4°C) 22 hours 28 hours 16 days
35°F (2°C) 64 hours 72 hours 18 days

Curing time varies with surface temperature, air movement, humidity, and film thickness. Note: Series 21 will continue to cure below 32°F (0°C), but at a slower speed. Please contact Tnemec Technical Services to discuss project-specific details. Note: Maximum recoat time with itself is 30 days.


Steel: Self-priming, Series 1, L69, L69F, N69, N69F, 91-H₂O, 94-H₂O, 98-H₂O, L140, L140F, N140, N140F, 394
Concrete: Self-priming, Series L69, L69F, N69, N69F, L140, L140F, N140, N140F, 215, 218
CMU: Self-priming or Series 215
Note: The following maximum recoat times apply; itself, 30 days; Series L69, N69, nine months; Series 1, L140, N140, 12 months.


Unthinned: 1.14 lbs/gal solids
Thinned 5% (No. 88 Thinner): 1.47 lbs/gal solids

Volatile Organic Compounds

Unthinned: 1.20 lbs/gallon (144 grams/litre)
Thinned 5% (No. 88 Thinner): 1.46 lbs/gallon (175 grams/litre) †

Recommended DFT

4.0 to 20.0 mils (100 to 510 microns). Note: Thickness requirements will vary with the substrate, application method, and exposure. Contact your Tnemec representative.

Theoretical Coverage

1,315 mil sq ft/gal (31.5 m²/L at 25 microns). See APPLICATION for coverage rates. †

Volume Solids

82% ± 2.0% (mixed) †

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